The present invention relates to corrugated pipes. More specifically, the invention relates to corrugated pipe structures that are joined together.
Corrugated pipes are joined together end to end to form sealed joints. This is facilitated by telescopic insertion of an open outer end of one pipe into an open outer end of another pipe.
In accordance with a first feature of the present invention, a pipe structure has an annular corrugation centered on an axis. The corrugation has a cylindrical liner centered on the axis, two annular sidewalls extending radially outward from axially opposite ends of the liner, and an annular crown extending axially between radially outer ends of the sidewalls. The pipe structure further has an annular cavity centered on the axis and bounded by the liner, the sidewalls and the crown. A structural filler is contained within the cavity.
In a preferred embodiment of the invention, the crown defines an annular groove extending radially inward and centered on the axis. An annular gasket is received within the groove, and is configured to provide a seal between the pipe structure and a section of another pipe structure that telescopically receives the pipe structure. The filler has a solid state attained by curing of the filler while confined within the cavity. In the preferred embodiment, the filler is preferably a foam with an expanded state that has an actual density that is greater than the freely expanded density of the foam.
In accordance with a second feature of the present invention, a pipe structure includes a bell centered on an axis. The bell has an open outer end and a barrel configured to telescopically receive a section of another pipe structure inserted inward through the open outer end. An annular backwall of the bell extends radially inward from the barrel. The pipe structure further includes a first corrugation axially adjacent to the bell. A reinforcing structure extends axially from the bell to the first corrugation, and constrains axial movement of the bell relative to the first corrugation.
In a preferred embodiment, the reinforcing structure is a ring that extends around the axis. An annular band is wrapped about the barrel and is configured to resist circumferential expansion of the barrel.
The present invention further comprises a method of reinforcing a bell of a pipe. A barrel of the bell has a radially inner surface that is configured to telescopically receive a section of another pipe. The method includes inserting a proving ring within the barrel. A strap is wrapped about the barrel with a tension that forces the radially inner surface of the barrel to adopt an inner circumference that equals the outer circumference of the proving ring. Subsequently, the strap is installed about the barrel to resist circumferential expansion of the radially inner surface of the barrel. The proving ring is then removed.
Another method of reinforcing a bell of a pipe includes wrapping a strap about the barrel. Two portions of the strap are fastened together to form the strap into a reinforcing band having a predetermined inner circumference. The inner circumference is chosen such that the band forces a radially inner surface of the barrel to adopt and maintain a desired inner circumference.